The demilitarized zone is series of systems between the territories of the Daelaam, Zerg Swarm and the Terran Dominion. No side is allowed to establish a military presence in the region aside from agreed upon bases, but the factions are allowed to send patrols. No civilians are allowed on planets in the DMZ aside from contracted support personnel.[1] After the End War, several Terran Dominion mining outposts were abandoned in this region.[2]

Some time after the One-Day War, marines under Captain Hogarth violated the demilitarized zone to steal jorium from the planet Adena. They were intercepted by Admiral Urun, who distrusted them but let them land. The team was then attacked by zerg forces under BroodmotherNiadra.[2] The Niadra Brood attempted to infest the squad's commander with a larva, but when she was evacuated in a dropship the protoss shot it down, inflaming tensions between the Daelaam and Terran Dominion forces.[3] Admiral Urun arrived on the planet's surface to deal with the zerg personally, allying with Elms and her marines stranded in their fight against the zerg. As the battle escalated, Niadra overwhelmed and killed Urun and his forces as they bought time for Elms and her squad to escape the zerg's clutches, and the protoss forces in orbit departed from the system.[4] Elms and her forces escaped the planet, leading Niadra to rally for a new strategy. Meanwhile, the violation of the demilitarized zone caused tensions between the Daelaam and Terran Dominion. In response to the Auriga Tribe's demand for action over Urun's death, HierarchArtanis withdrew his peace talks with the Dominion.[5]

On Cavir, the Dominion was allowed to maintain a military base and patrol the world, often coming across zerg. Many illegal miners operated on the planet.[1] However, these miners soon agitated the zerg, who were united under a queen, resulting in the zerg to attack the Dominion on the world at the Battle of Camp Pitcairn. The Dominion were able to kill the queen and drive the zerg back.[6]